POWER OF ATTORNEY

        KNOW ALL BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints Julia Wright as the undersigned's true and lawful attorney-in-fact to:

              (1)     prepare, execute and submit, for and on behalf of the
undersigned, a Form ID and amendments thereto and any other documents necessary
or appropriate to obtain codes and passwords enabling the undersigned to make
electronic filings with the Securities and Exchange Commission (the
"Commission");

              (2)     prepare and execute, for and on behalf of the undersigned,
in the undersigned's capacity as an officer and/or director of Apergy
Corporation (the "Company"), all forms to be filed by the undersigned pursuant
to Section 16(a) of the Securities Exchange Act of 1934, as amended, and the
rules and regulations promulgated thereunder (the "Exchange Act"), and Rule 144
under the Securities Act of 1933, as amended, and the rules and regulations
promulgated thereunder (the "Securities Act"), including Forms 3, 4, 5 and 144
and any successor forms (collectively, the "Forms");

              (3)     do and perform any and all acts for and on behalf of the
undersigned that may be necessary or desirable to prepare and execute any such
Forms, and file all such Forms and any amendment thereto with the Commission and
any stock exchange or similar authority; and

              (4)     take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact, may be of
benefit to, in the best interest of, or legally required to be done by, the
undersigned, it being understood that the Forms executed by such attorney-in-
fact on behalf of the undersigned pursuant to this Power of Attorney shall be in
such form and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

        The undersigned hereby grants to the attorney-in-fact full power and
authority to do and perform each and every act and thing requisite, necessary or
proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney-in-fact, or such attorney-in-
fact's substitute or substitutes, shall lawfully do or cause to be done by
virtue of this Power of Attorney and the rights and powers herein granted.  The
undersigned acknowledges that the foregoing attorney-in-fact, in serving in such
capacity at the request of the undersigned, is not assuming, nor is the Company
assuming, any of the undersigned's responsibilities to comply with Section 16 of
the Exchange Act or Rule 144 under the Securities Act.

        This Power of Attorney shall be effective as of the date set forth below
and shall remain in full force and effect until the undersigned is no longer
required to file the Forms with respect to the undersigned's holdings of and
transactions in securities of the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorney-in-fact.

        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 4th day of April, 2018.


                                        By: /s/ Amy T. Broussard
                                            -----------------------------------
                                        Name: Amy Thompson Broussard